Science Lecture for Unit 54: The Bohr Atom
- Topic area: Physics and Chemistry: atomic structure
- Terms and concepts to know: proton, electron, neutron, isotope, nucleus, atomic mass, atomic number, elements, electron structure.
- See historical period(s): Discovery of radioactivity
More Atom Basics
Read about the development of the empty atom concept and the Bohr atom. [2 moderate web pages.] Don't focus on the mathematics, but try to understand the key relationships involved: what physical entities are being described? For example, 1/2mv2 is kinetic energy.
- Rutherford discovered that radioactivity decreases geometrically as time passes. How is a geometric progression different from an arithmetic progression?
- How do we explain the very small deflection most alpha particles experience passing near the nucleus?
- Why does direct deflection back from the foil disprove the "plum pudding" model?
- What is a hyperbolic path? How does it differ from a parabolic path or a circular path?
- Why was large angle scattering important in determining the size of the nucleus?
- What did Rutherford originally think the α particle was made of?
- Can an electron have an orbit of any radius when it is part of an atom? Why is this a problem for classical mechanics?
- How is the kinetic energy of an electron related to frequency? What does this frequency measure?
- What did Richard Whiddington's experiments with x-rays show about atoms?
- What is Balmer's formula? What does it predict? What is "n" in the formula?
- How are the radius and speed of the orbit of an electron proportional to "n"?
A more graphic treatment of the different parts of the atom is presented at the Trium Safety Group site, by Noel Griffin.
[7 really short web pages with graphics: read them all:
- Atomic structure
- The Nucleus and Electrons
- Atomic Number
- Atomic Mass
- Electron Orbits
- The size of the electron
- Chemical symbols
- Why is a fixed structure hard to describe for the atom?
- How many types of atoms occur "naturally"? How are "unnatural" atoms produced?
- Why is the mass of the electron usually ignored when determining the mass of an atom?
- What is an electron shell?
- What parts of the atom are affected by chemical reactions (such as the recombination of sugar molecules into carbon dioxide and water)?
- Roughly how much larger than the nucleus is the atom with its electron shell?
- How do ions and isotopes change the number of particles in an atom?
Further Study On your Own (Optional)
- No extra links this time!
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